It's been heralded by politicians, experts and industry leaders as a momentous event for Australian history but the complexity of the deal has also left many scratching their heads.

Let us break it down for you.

Australia is getting nuclear-powered submarines but don't expect them to be gliding through oceans any time soon.

Prime Minister Anthony Albanese, alongside US President Joe Biden and UK Prime Minister Rishi Sunak, revealed the details of the nuclear-powered submarine technology sharing agreement on Tuesday.

The deal means Australia will get three US-built off-the-shelf Virginia class submarines starting in the early 2030s, pending US Congressional approval.

There's also the potential for Australia to purchase up to two more Virginia class submarines if needed.

Five AUKUS submarines, which bring together UK ship designs with a US combat system, will begin being built in South Australia from the 2030s.

One is expected to be delivered every three years from around 2042.

Defence Minister Richard Marles said the entire project is estimated to cost 0.15 per cent of GDP with some estimating the bill will reach between $268 billion to $368 billion over its lifetime.

As the federal government repeated a number of times during the announcement - jobs.

It's expected around 20,000 Australian jobs will be generated over the next three decades with 8500 directly-employed workers anticipated at the project's peak.

Those jobs will be across a wide array of fields, including submariners, engineers, scientists and bureaucrats.

On a world stage, it will also mean Australia will become just the seventh country to have access to nuclear-powered propulsion technology.

The six other countries with the technology include the US, the UK, France, China, Russia and India.

The addition to Australia's naval armaments will also be used as a deterrent in the region's military space as tensions continue to rise in the Indo-Pacific region.

"As a trading island nation, so much harm can be done to us before ever setting foot upon our shores," Mr Marles said.

"So it's fundamentally important for our nation that we have the ability to project, and to project with impact."

The first custom-built submarines won't hit the high seas for another two decades. It's expected the first AUKUS submarine built in Australia will meet water from 2042.

In the interim, it's expected the US will sell its Virginia class submarines so that Australia will have a sovereign nuclear-powered option to use from around 2033.

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In order for defence personnel to be brought up to speed with the technology, US Navy will forward deploy Virginia class submarines to Western Australia from 2027.

The British Royal Navy will also rotate to Australia to help acquaint Australian naval personnel with the UK's Astute class, which the final AUKUS design is partially based upon.

Starting this year, Australian military and civilian personnel will be sent to the US Navy and British Royal Navy to begin initial training and development.

As leaders announced in San Diego, Tuesday's AUKUS announcement is "only the beginning".

So, other than nuclear-powered submarines, what else can we expect?

For starters, it's always been pitched as a deal that's "more than just subs" though it would be hard to tell from Tuesday's headlines.

Months after the AUKUS pact was announced in 2021, then-UK and Australian prime ministers Boris Johnson and Scott Morrison joined President Biden to announce the three countries would work together to build hypersonic and counter-hypersonic technology.

Hypersonic missiles have reportedly been used by Russia during its invasion in Ukraine and can travel five times the speed of sound and many times faster than conventional missiles.

The US and China are both reportedly working on their own hypersonic missile technology.

The AUKUS deal is also expected to have greater emphasis on intelligence sharing, building upon the existing Five Eyes alliance.

For now, those remain announcements for another sunny day on a military base somewhere.